Jamming Model Research Articles

Influence of Double Stealth Aircraft Approach Forward Support Cooperative Jamming on Radar Detection Performance

Aiming at the single stealth aircraft approaching support jamming, the support jamming suppression ability is insufficient, and if the jamming power is too large, it will be tracked and located. With the increase of hazard coefficient, a model of double stealth aircraft cooperative proximity support jamming is proposed. Based on solving the attitude angle of two aircraft, comparing with the static RCS database in the whole airspace and simulating the time-varying RCS of two aircraft, the influence degree of detection distance of monostatic radar is analyzed and verified by simulation using power co-suppression method. The results show that when the formation of two aircraft is 1 km, the suppression effect of the cooperative suppression and shielding task aircraft is better, which can effectively reduce its RCS, reduce the radar detection distance, improve the cooperative jamming effect and enhance the overall conduct operations level.Chinese Classification Number: V218; TN972+.1Document Identification Code: A

Polarimetric multiple-radar architectures with distributed antennas for discriminating between radar targets and deception jamming

The potential abilities of polarimetric multiple-radar architectures with distributed antennas in electronic counter-countermeasures (ECCMs) are analyzed based on differences between target echoes and deception jamming in scattering coefficients properties. According to the differences in generation mechanism between the target scatter and jamming, a signal model of real targets and deception jamming for two-dimensional vector sensors is established. By applying the Neyman-Pearson (NP) criterion and a hybrid NP-Maximum Posteriori (MAP) criterion, a two-stage detection/discrimination algorithm is proposed. In our proposed algorithm, the targets and jamming are detected in the first stage from a Gaussian noise background. Then, a discriminator based on the generalized likelihood ratio test is designed by exploiting the property of polarization discrimination. A theoretical analysis is also given to evaluate the performance of the second stage of the algorithm. Moreover, the discrimination performance can be improved by optimizing the transmitter polarization parameters. Simulation results indicate that the proposed ECCM strategy is effective against DRFM jamming, especially when JNR is high and transmit polarization is optimally designed.

Anti-Jamming Technology of SAR Seeker for Forward Squint of Aircaft

The SAR seeker has the capability of detecting all day long and all-weather. The imaging guidance of SAR can revise the error of inertial navigation, greatly improved the precision of the aircraft. However, the SAR seeker is vulnerable to interference from the other side, which affects imaging and guidance capability. In this paper, the basic principle, model and jamming effect of common noise, FM jamming and pulse jamming are given on the basis of introducing the working principle of SAR seeker. On this basis, this paper focuses on the anti-noise and anti-pulse jamming technology and interference principle of the SAR seeker with forward squint. After analysis, the anti-jamming principle is feasible, and it has the engineering application ability, and can be applied to the aircraft. In addition, from the point of view of the overall design of aircraft, some anti-jamming ideas of SAR seeker are given.

A Game-Theoretic Learning Approach for Anti-Jamming Dynamic Spectrum Access in Dense Wireless Networks

In this paper, we investigate the anti-jamming channel selection problem for interference mitigation (IM) based dense wireless networks in dynamic environment, in which the active user set is variable due to their specific traffic demands. We jointly consider the mutual interference among users and external jamming in IM-based dense wireless networks, and propose a generalized maximum protocol interference and jamming model to accurately capture the mutual interference and external jamming. Then, the anti-jamming channel selection problem is formulated as an anti-jamming dynamic game, and subsequently it is proved to be an exact potential game, which has at least one pure strategy Nash equilibrium (NE). Based on the stochastic learning theory, a distributed anti-jamming channel selection algorithm (DACSA) is proposed to find the NE solution. Moreover, the simulation results are presented to demonstrate the effectiveness of the proposed DACSA algorithm.

Comparing Gausian and exact models of malicious interference in VLC systems

Visible Light Communication (VLC) is a technique for high-speed, low-cost wireless data transmission based on LED luminaries. Wireless LAN environments are a major application of VLC. In these environments, VLC is used in place of traditional systems such as Wi-Fi. Because of the physical characteristics of visible light, VLC is considered to be superior to traditional radio-based communication in terms of security. However, as in all wireless systems, the security of VLC with respect to eavesdropping, signal jamming and modification must be analyzed. This paper focuses on the aspect of jamming in VLC networks. In environments where multiple VLC transmitters are used, there is the possibility that one or more transmitters will be hostile (or rogue). This leads to communication disruption, and in some cases, the hijacking of the legitimate data stream. In this paper we present the theoretical system model that is used in simulations to evaluate various rogue transmission scenarios in a typical indoor environment. The typical approach used so far in jamming analysis assumes that all disruptive transmissions may be modeled as Gaussian noise, but this assumption may be too simplistic. We analyze and compare two models of VLC jamming: the simplified Gaussian and the exact model, where the full characteristics of the interfering signal are taken into account. Our aim is to determine which methodology is adequate for studying signal jamming in VLC systems.

Real-Time Jamming DoS Detection in Safety-Critical V2V C-ITS Using Data Mining

A data-mining-based method for real-time detection of radio jamming denial-of-service attacks in the IEEE 802.11p vehicle-to-vehicle (V2V) communications is proposed. The method aims at understanding the reasons for losses of periodic cooperative awareness messages (CAMs) exchanged by vehicles in a platoon. Detection relies on a knowledge of the IEEE 802.11p protocol rules as well as on the historical observation of events in the V2V channel. In comparison with the state-of-the-art method, the proposed method allows operating under the realistic assumption of random jitter accompanying every CAM transmission. The method is evaluated for two jamming models: random and ON-OFF.

A Barrage Noise Jamming Method Based on Double Jammers Against Three Channel SAR GMTI

Many jamming methods have been proposed against displaced phase center antenna (DPCA) process, which is a type of three-channel synthetic aperture radar (SAR) ground moving target indication. However, two important problems faced by the jammer are why the jamming based on a single jammer is suppressed and how to generate noise in the whole DPCA image while keeping its easy realization. By analyzing a jamming geometric model based on a single jammer, the reason is that the phase of the jamming image in different antennas is only relative to the jamming geometric model, which contains the azimuth position of the jammer and jamming in the SAR image. Then, the jamming area is classified as an enhanced area and a weakened area after DPCA processing. Moreover, the jamming in the weakened area will be suppressed. To overcome this disadvantage, a barrage noise jamming method based on double jammers is proposed. By controlling the azimuth distance between the jammers, the noise can cover the whole DPCA image. Compared with the deception jamming method based on multiple coherent jammers, the phase and amplitude of the jamming signal do not need to be accurately controlled. Finally, the validity of the proposed method is verified by simulation experiments.

Research on Airspace Planning for Stand-off and Compound Jamming

A radar adopts anti-jamming techniques such as side lobe cancellation and moving target indication, resulting in the worsening of the effects of single active jamming and passive jamming. Therefore a compound jamming strategy was proposed and can effectively respond to the anti-jamming device of the new radar. The conditions for the use of this strategy were defined. Based on the military airspace planning principles, taking into account human error, wind and other errors, the specific process of airspace planning was elaborated. Taking into account the effects of compound jamming and the safety of a jammer, an airspace model for stand-off and compound jamming was established. The Whale Optimization Algorithm (WAO) with Tent chaotic sequence was used to solve the model and the airspaces with different preferences were planned. The simulation results show that the model is scientific and effective. The optimization ability of the WOA of with tent chaotic sequence is better than WAO. In addition, the planning direction is quite different in Simulation 1 and Simulation 2, with a maximum of 99°. The compound jamming for stand-off jamming in airspace planning is more flexible and has more advantages in multiple military planning airspaces.

Cumulants of the baryon number from central Au+Au collision at Elab=1.23 GeV/nucleon reveal the nuclear mean-field potentials

Fluctuations of the baryon number in relativistic heavy-ion collisions are a promising observable to explore the structure of the QCD phase diagram. The cumulant ratios in heavy ion collisions at intermediate energies ($\sqrt{s_{\textrm{NN}}} < 7$ GeV) have not been studied to date. We investigate the effects of mean field potential and clustering on the cumulant ratios of baryon and proton number distributions in Au+Au collisions at beam energy of 1.23 GeV$/$nucleon as measured by the HADES Collaboration at GSI. Ultrarelativistic Quantum Molecular Dynamics (UrQMD) and the JAM model are used to calculate the cumulants with different mean field potentials. It is found that the cumulant ratios are strongly time dependent. At the early stage, the effects of the potentials on the fluctuations of the particle multiplicity in momentum space are relatively weak. The mean fields enhance the fluctuations during the expansion stage, especially for small rapidity acceptance windows. The enhancement of cumulant ratios for free protons is strongly suppressed as compared to that for all baryons. The mean field potentials and the clustering play an important role for the measured cumulant ratios at intermediate energy.

Two-Dimensional Antijamming Mobile Communication Based on Reinforcement Learning

By using smart radio devices, a jammer can dynamically change its jamming policy based on opposing security mechanisms; it can even induce the mobile device to enter a specific communication mode and then launch the jamming policy accordingly. On the other hand, mobile devices can exploit spread spectrum and user mobility to address both jamming and interference. In this paper, a two-dimensional anti-jamming mobile communication scheme is proposed in which a mobile device leaves a heavily jammed/interfered-with frequency or area. It is shown that, by applying reinforcement learning techniques, a mobile device can achieve an optimal communication policy without the need to know the jamming and interference model and the radio channel model in a dynamic game framework. More specifically, a hotbooting deep Q-network based two-dimensional mobile communication scheme is proposed that exploits experiences in similar scenarios to reduce the exploration time at the beginning of the game, and applies deep convolutional neural network and macro-action techniques to accelerate the learning speed in dynamic situations. Several real-world scenarios are simulated to evaluate the proposed method. These simulation results show that our proposed scheme can improve both the signal-to-interference-plus-noise ratio of the signals and the utility of the mobile devices against cooperative jamming compared with benchmark schemes.

Molecular Communications Pulse-Based Jamming Model for Bacterial Biofilm Suppression.

Studies have recently shown that the bacteria survivability within biofilms is responsible for the emergence of superbugs. The combat of bacterial infections, without enhancing its resistance to antibiotics, includes the use of nanoparticles to quench the quorum sensing of these biofilm-forming bacteria. Several sequential and parallel multi-stage communication processes are involved in the formation of biofilms. In this paper, we use proteomic data from a wet lab experiment to identify the communication channels that are vital to these processes. We also identified the main proteins from each channel and propose the use of jamming signals from synthetically engineered bacteria to suppress the production of those proteins. This biocompatible technique is based on synthetic biology and enables the inhibition of biofilm formation. We analyze the communications performance of the jamming process by evaluating the path loss for a number of conditions that include different engineered bacterial population sizes, distances between the populations, and molecular signal power. Our results show that sufficient molecular pulse-based jamming signals are able to prevent the biofilm formation by creating lossy communications channels (almost -3 dB for certain scenarios). From these results, we define the main design parameters to develop a fully operational bacteria-based jamming system.

Outfield experiment of semiconductor laser jamming on color CCD camera

Outfield laser jamming experiment of color charge coupled device (CCD) irradiated by semiconductor laser was performed. The impact of incident power density I0 and the focus length f on laser jamming results was obtained. Laser jamming model of color CCD camera is set up, and theoretical proving and analysis on experimental results are completed. Laser jamming effects on color CCD camera irradiated by semiconductor laser is obvious, CCD surface appears obvious optical saturation and crosstalk phenomena, and optical saturation areas gradually enlarge with the increase of power density to target and the focus length f. Simulation results are basically coincident with experimental results, and it proves laser jamming model is correct. We argue that optical saturation phenomenon should be caused by laser diffraction effect, and the impact of the focus length f should be mainly due to laser energy truncated by the aperture. The conclusions have a reference value for color CCD in aerospace.

HUBUNGAN ANTARA STATUS GIZI DAN TINGKAT ASUPAN ZAT GIZI DENGAN SIKLUS MENSTRUASI PADA REMAJA PUTRI DI KECAMATAN KEDUNGBANTENG KABUPATEN BANYUMAS

Background: Menstrual disorders often occur among adolescent girls. Menstrual disorder due to several factor including nutritional status, age, physical activity, nutrients intake, disease, stress and influence of cigarettes .&#x0D; &#x0D; Objective: To examined the association between nutritional status and level of nutrients intake with menstrual cycle among aldolescent in Distric Kedungbanteng Banyumas.&#x0D; &#x0D; Methods: Design research is analytic observation with cross sectional approach. Sampling technique used purposive sampling and obtained 69 respondent adolescent girls. The technique of data colelection used menstrual cycle questionnaire, antropometric, food recall 2x24 jam, food picture and food model.&#x0D; &#x0D; Result: There is 40.6% respondent have an abnormal menstrual cycle. Nutritional status (11.6%) classified abnormal. Energy intake (91.3%), carbohydrate (94.2%) protein intake (89.9%) and fat intake (85.5%) classified an abnormal. Based on analysis of Chi-Square test, there is a significant relation between fat intake with menstrual cycle (p=0.041).&#x0D; &#x0D; Conclusion: Fat intake associated with menstrual cycle..

Signal jamming models of fraudulent misreporting and economic prospects: An experimental investigation

This study uses experimental methodology to examine how the frequency and magnitude with which managers commit fraud varies with economic prospects (Boom, Middle and Bust). The experimental design is based on signal-jamming equilibrium (SJE) models of fraud in which managers make potentially inaccurate public reports and investors bid on shares. Under SJE, managers always exaggerate reports by a fixed amount up to the maximum possible report, independent of the truth. Shareholders can perfectly correct managers' reports (except for the maximum possible report). In contrast, the results of the experiment show four robust deviations from SJE predictions: (1) managers exaggerate and shareholders correct reports according to dominated mixed-strategies with probabilities significantly less than one, (2) managers exaggerate more frequently and by more when outcomes are poor, (3) shareholders adjust low reports by less than high reports, and (4) shareholders correct relatively high reports by more in booms than busts even though managers' reporting strategies are invariant to economic prospects.

UAV Relay in VANETs Against Smart Jamming With Reinforcement Learning

Frequency hopping-based antijamming techniques are not always applicable in vehicular ad hoc networks (VANETs) due to the high mobility of onboard units (OBUs) and the large-scale network topology. In this paper, we use unmanned aerial vehicles (UAVs) to relay the message of an OBU and improve the communication performance of VANETs against smart jammers that observe the ongoing OBU and UAV communication status and even induce the UAV to use a specific relay strategy and then attack it accordingly. More specifically, the UAV relays the OBU message to another roadside unit (RSU) with a better radio transmission condition if the serving RSU is heavily jammed or interfered. The interactions between a UAV and a smart jammer are formulated as an antijamming UAV relay game, in which the UAV decides whether or not to relay the OBU message to another RSU, and the jammer observes the UAV and the VANET strategy and chooses the jamming power accordingly. The Nash equilibria of the UAV relay game are derived to reveal how the optimal UAV relay strategy depends on the transmit cost and the UAV channel model. A hotbooting policy hill climbing-based UAV relay strategy is proposed to help the VANET resist jamming in the dynamic game without being aware of the VANET model and the jamming model. Simulation results show that the proposed relay strategy can efficiently reduce the bit error rate of the OBU message and thus increase the utility of the VANET compared with a Q-learning-based scheme.

MuseGAN: Multi-track Sequential Generative Adversarial Networks for Symbolic Music Generation and Accompaniment

Generating music has a few notable differences from generating images and videos. First, music is an art of time, necessitating a temporal model. Second, music is usually composed of multiple instruments/tracks with their own temporal dynamics, but collectively they unfold over time interdependently. Lastly, musical notes are often grouped into chords, arpeggios or melodies in polyphonic music, and thereby introducing a chronological ordering of notes is not naturally suitable. In this paper, we propose three models for symbolic multi-track music generation under the framework of generative adversarial networks (GANs). The three models, which differ in the underlying assumptions and accordingly the network architectures, are referred to as the jamming model, the composer model and the hybrid model. We trained the proposed models on a dataset of over one hundred thousand bars of rock music and applied them to generate piano-rolls of five tracks: bass, drums, guitar, piano and strings. A few intra-track and inter-track objective metrics are also proposed to evaluate the generative results, in addition to a subjective user study. We show that our models can generate coherent music of four bars right from scratch (i.e. without human inputs). We also extend our models to human-AI cooperative music generation: given a specific track composed by human, we can generate four additional tracks to accompany it. All code, the dataset and the rendered audio samples are available at https://salu133445.github.io/musegan/.

Target deception jamming method against spaceborne synthetic aperture radar using electromagnetic scattering

A method is proposed to perform target deception jamming against spaceborne synthetic aperture radar. Compared with the traditional jamming methods using deception templates to cover the target or region of interest, the proposed method aims to generate a verisimilar deceptive target in various attitude with high fidelity using the electromagnetic (EM) scattering. Based on the geometrical model for target deception jamming, the EM scattering data from the deceptive target was first simulated by applying an EM calculation software. Then, the proposed jamming frequency response (JFR) is calculated offline by further processing. Finally, the deception jamming is achieved in real time by a multiplication between the proposed JFR and the spectrum of intercepted radar signals. The practical implementation is presented. The simulation results prove the validity of the proposed method.

Anti-Jamming Underwater Transmission With Mobility and Learning

In this letter, we present an anti-jamming underwater transmission framework that applies reinforcement learning to control the transmit power and uses the transducer mobility to address jamming in underwater acoustic networks. The deep $Q$ -networks-based transmission scheme can achieve the optimal power and node mobility control without knowing the jamming model and the underwater channel model in the dynamic game. Experiments performed with transducers in a non-anechoic pool show that our proposed scheme can reduce the bit error rate of the underwater transmission against reactive jamming compared with the $Q$ -learning based scheme.

Mechanically Versatile Soft Machines through Laminar Jamming

AbstractThere are two major structural paradigms in robotics: soft machines, which are conformable, durable, and safe; and traditional rigid robots, which are fast, precise, and capable of applying high forces. Here, the paradigms are bridged by enabling soft machines to behave like traditional rigid robots on command. This task is accomplished via laminar jamming, a structural phenomenon in which a laminate of compliant strips becomes strongly coupled through friction when a pressure gradient is applied, causing dramatic changes in mechanical properties. Rigorous analytical and finite element models of laminar jamming are developed, and jamming structures are experimentally characterized to show that the models are highly accurate. Then jamming structures are integrated into soft machines to enable them to selectively exhibit the stiffness, damping, and kinematics of traditional rigid robots. The models allow jamming structures to efficiently meet arbitrary performance specifications, and the physical demonstrations illustrate how to construct systems that can behave like either soft machines or traditional rigid robots at will, such as continuum manipulators that can rapidly have joints appear and disappear. This study aims to foster a new generation of mechanically versatile machines and structures that cannot simply be classified as “soft” or “rigid.”

The EDGE–CALIFA survey: validating stellar dynamical mass models with CO kinematics

Abstract Deriving circular velocities of galaxies from stellar kinematics can provide an estimate of their total dynamical mass, provided a contribution from the velocity dispersion of the stars is taken into account. Molecular gas (e.g. CO), on the other hand, is a dynamically cold tracer and hence acts as an independent circular velocity estimate without needing such a correction. In this paper, we test the underlying assumptions of three commonly used dynamical models, deriving circular velocities from stellar kinematics of 54 galaxies (S0-Sd) that have observations of both stellar kinematics from the Calar Alto Legacy Integral Field Area (CALIFA) survey, and CO kinematics from the Extragalactic Database for Galaxy Evolution (EDGE) survey. We test the asymmetric drift correction (ADC) method, as well as Jeans, and Schwarzschild models. The three methods each reproduce the CO circular velocity at 1Re to within 10 per cent. All three methods show larger scatter (up to 20 per cent) in the inner regions (R &lt; 0.4Re) that may be due to an increasingly spherical mass distribution (which is not captured by the thin disc assumption in ADC), or non-constant stellar M/L ratios (for both the JAM and Schwarzschild models). This homogeneous analysis of stellar and gaseous kinematics validates that all three models can recover Mdyn at 1Re to better than 20 per cent, but users should be mindful of scatter in the inner regions where some assumptions may break down.